New 15.5x20 Michelins Beating The Crap Out of Me!

-YES- I searched.

Mounted up new Michelin 15.5x20 tires on 10" wide wheels from Clint.

At freeway speeds they just beat the heck out of me. You don't want to drive this truck with a couple of cups of coffee in you

OW!

What the driver and passenger gets is a real good shaking that comes right through the seat at 45+ MPH.

I started out with 70 lbs of air pressure. Then I tried searching SS for "air pressure" and read all the posts about that. I lowered the Air Pressure to 60lbs. Still shakes the crap out of ya!

Searched and read some more. Looks like some fellows are running Real Low Air Pressure, around 35 to 40 lbs.

That seems real low.

So what's the scoop? At what air pressure will this thing smooth out and make it driveable?

Planning for a real long trip tomorrow, and first time my wife rides in it except for getting coffee, so I want to give that nice tolerant woman a nice ride in Esmerelda!

Thanks everyone!!

Thats what I have been told too. Lower pressure.

Yup get the air pressure lower... you might need to have them partially balanced as well

gimpyrobb said:

Thats what I have been told too. Lower pressure.

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So how low? There is so much air in those tires it is a real project just to adjust it. About one beer per side!

MilitaryRestoration said:

Yup get the air pressure lower... you might need to have them partially balanced as well

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Thanks! Who do you know in the Portland-Vantucky area can balance a tire that big?

I have about 50psi in my 395/85s. I was told 40 or lower. Might try max rated(95psi) for shucks, but the guys here have "been there done that" no need to re-invent the wheel. Take their advice.

Dan, have you used those? I took my truck out for a test drive Sunday and aside from the bounce of bumps, I didn't think I needed to balance my tires. Looks like a slow process for tube tires bigger than stock.

gimpyrobb said:

Looks like a slow process for tube tires bigger than stock.

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Just butt a palm sander on the valve stem to make it go faster.

Tire pressure shuld be 45psi. You will need 1 or 2 - 1 pound shot bags for dynamic balancing. Also make sure wheels are true. 1/8 of an inch off @ the hub = inches @ the outside of the tires.

schwab in yakima can balance my 52's so i would assume someone in portland can do 15.5's and yes byna beads are great too with tubeless tires, btw that link isn't working for me dan...

nm was my computer in general, had to reset modem, now working

frodobaggins said:

Just butt a palm sander on the valve stem to make it go faster.

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The Dynabead guys used an engraver tool. I can't imagine putting 14oz in the valvestem like that. Easier just to pop the bead at a tire shop and throw in a 14oz bag, then re-seat the bead and inflate. Done and done.

I have not used them yet, but it's on my list.

what was that other company we were looking at that i could never get a hold of...? do you remember dan?

also why is the amount of beads needed different from Large Commercial rigs click here compared to 4x4 & oversize tire owners clcik here but using same tire size... ie 16.00 x 20 commercial says 16oz where in the oversize section says 36oz thats quite a big difference

DanMartin said:

The Dynabead guys used an engraver tool. I can't imagine putting 14oz in the valvestem like that. Easier just to pop the bead at a tire shop and throw in a 14oz bag, then re-seat the bead and inflate. Done and done.

I have not used them yet, but it's on my list.

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Not in a tube...

I will try the 45lbs and see how that works then. Dynabead recommends 25oz in a 15.5x20 tire.

i have mine at 50psi they are smooth.i would check things out they ussually get better with more pressure.any problem that was htere before will be greatly exacerated with more rotating weight .my truck drove fine two days after i put the 15.5s on my left front wheel bearing showed me it was bad when it decided to let go on the e way

hey beerslayer.. by chance where did the tires come from and you can pm if you dont want to post pubically, but I may have a good explanation as to why your tires may be doing that... and it may not be fixable... :-/ let me know

I'm interested in hearing about what wheels/tires you're running too.